Bottom Line:
Double-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion.We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging.

ABSTRACTDouble-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion. We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging.

Mentions:
A 26-year-old man was referred to the hospital for the evaluation of his abnormal cardiac murmur found during a routine health examination program. The patient had no cardiac symptoms, such as chest pain or dyspnea. During the physical examination, a prominent grade 5/6 systolic ejection murmur was heard on the left parasternal border. His blood pressure was 110/72 mmHg, and his heart rate was 66/min. In addition to mild cardiomegaly on the chest radiography, the electrocardiogram showed increased amplitude of the R wave on V1 and inverted T waves on V1-V3, suggesting right ventricular overload. The two-dimensional (2-D) transthoracic echocardiogram on the parasternal short axis view showed a marked muscle band protruding from the right ventricular free wall to the interventricular septum (Fig. 1A). In addition, right atrial enlargement, right ventricular hypertrophy and dilation, and moderate tricuspid regurgitation were found. A turbulent Doppler color flow jet with a mosaic pattern was seen through the stenotic mid-right ventricle on the parasternal short axis view (Fig. 1B). Continuous wave Doppler revealed tricuspid regurgitation between the right atrium and right ventricle with a flow acceleration of 7.0 m/s, corresponding to a pressure gradient of 196 mmHg calculated using the simplified Bernoulli equation (Δp=4ν2) (Fig. 1C).3) Transesophageal echocardiography demonstrated an anomalous muscle bundle dividing the right ventricle into two parts (Fig. 2). There was no shunt flow between the right and left parts of the heart. In addition, cardiac magnetic resonance imaging (MRI) revealed that hypertrophied muscle bundles transected the right ventricle from the free wall to the ventricular septum, resulting in the division of the right ventricle into two chambers (Fig. 3). Coronary angiography revealed normal coronary arteries; however the right ventriculogram demonstrated severe right ventricular muscle bundle hypertrophy, separating the right ventricle into the inflow and outflow chambers (Fig. 4). Cardiac catheterization was performed, and the pull-back pressure from right heart catheterization was recorded. The systolic pressure of the right ventricular inlet and the outlet pressure were 135 and 25 mmHg respectively, while the pressure gradient of the right ventricle was 110 mmHg (Fig. 5). There was no pressure gradient between the right ventricle outlet tract and the main pulmonary artery. Based on these findings, the patient was referred to a thoracic and cardiovascular surgery clinic for surgical correction, but the patient refused operative correction and was thus discharged, with local follow up.

Mentions:
A 26-year-old man was referred to the hospital for the evaluation of his abnormal cardiac murmur found during a routine health examination program. The patient had no cardiac symptoms, such as chest pain or dyspnea. During the physical examination, a prominent grade 5/6 systolic ejection murmur was heard on the left parasternal border. His blood pressure was 110/72 mmHg, and his heart rate was 66/min. In addition to mild cardiomegaly on the chest radiography, the electrocardiogram showed increased amplitude of the R wave on V1 and inverted T waves on V1-V3, suggesting right ventricular overload. The two-dimensional (2-D) transthoracic echocardiogram on the parasternal short axis view showed a marked muscle band protruding from the right ventricular free wall to the interventricular septum (Fig. 1A). In addition, right atrial enlargement, right ventricular hypertrophy and dilation, and moderate tricuspid regurgitation were found. A turbulent Doppler color flow jet with a mosaic pattern was seen through the stenotic mid-right ventricle on the parasternal short axis view (Fig. 1B). Continuous wave Doppler revealed tricuspid regurgitation between the right atrium and right ventricle with a flow acceleration of 7.0 m/s, corresponding to a pressure gradient of 196 mmHg calculated using the simplified Bernoulli equation (Δp=4ν2) (Fig. 1C).3) Transesophageal echocardiography demonstrated an anomalous muscle bundle dividing the right ventricle into two parts (Fig. 2). There was no shunt flow between the right and left parts of the heart. In addition, cardiac magnetic resonance imaging (MRI) revealed that hypertrophied muscle bundles transected the right ventricle from the free wall to the ventricular septum, resulting in the division of the right ventricle into two chambers (Fig. 3). Coronary angiography revealed normal coronary arteries; however the right ventriculogram demonstrated severe right ventricular muscle bundle hypertrophy, separating the right ventricle into the inflow and outflow chambers (Fig. 4). Cardiac catheterization was performed, and the pull-back pressure from right heart catheterization was recorded. The systolic pressure of the right ventricular inlet and the outlet pressure were 135 and 25 mmHg respectively, while the pressure gradient of the right ventricle was 110 mmHg (Fig. 5). There was no pressure gradient between the right ventricle outlet tract and the main pulmonary artery. Based on these findings, the patient was referred to a thoracic and cardiovascular surgery clinic for surgical correction, but the patient refused operative correction and was thus discharged, with local follow up.

Bottom Line:
Double-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion.We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging.

ABSTRACTDouble-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion. We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging.